I. Field of the Invention
This invention relates generally to material handling equipment and, more particularly, to a lifting device attached to a refuse vehicle for handling containers during collection efforts.
II. Related Art
Mechanized material handling devices often include a container holder or grasping device connected to an arm which is connected to a base, such as a vehicle. The arm and grasping device are operated to engage a container of interest, lift and dump the container into a receiving hopper in the vehicle.
A representative example of such a device appears in U.S. Pat. No. 5,391,039, issued to Holtom, which describes a refuse loader arm including a lift limb and a reach limb articulated to one another at a pivot point. The lift limb is vertically pivotally attached at one end to a refuse vehicle and the reach limb is articulated at its other end to a bin grasping assembly which is held at a constant angle to the lift limb by a parallelogram linkage. The lift limb and the reach limb pivot in a common plane to reach out and grasp the container of interest and lift and dump the container. Of course, the vehicle must be positioned directly alongside such that the container is aligned with the pivoting plane of the arm. U.S. Pat. No. 5,330,308, issued to Armando et al., describes a refuse container loading device including a tubular support attached to a refuse vehicle, operable to pivot in a horizontal plane. A telecopying arm that pivots vertically is attached to the base and to a bin grasping device that is able to pivot a limited amount vertically and swivel horizontally.
Similarly, U.S. Pat. No. 4,175,903, issued to Carson, describes an apparatus for picking up containers wherein a boom arm is attached to a platform which is pivotally attached to a refuse vehicle for rotating in a generally horizontal plane. The boom arm is pivotally attached to the platform for pivoting vertically to raise and dump a container. A pick-up arm is provided to grasp the container and is attached to the boom arm with the ability to rotate in essentially a horizontal plane. Using the devices described in the ""308 and ""903 patents eliminates the need for precise positioning of the vehicle. But, the lift and dump arms are quite complex.
A principle object of the invention then is to provide an improved lifting device for handling objects or containers of interest.
Another object of the invention is to provide a relatively simple lifting device attached to a vehicle which eliminates the need for precise positioning of the vehicle.
Still another object of the invention is to provide a lifting device which includes an articulated arm disposed to pivot in one plane and rotatably attached to the vehicle for swiveling in another plane.
Yet another object of the invention is to provide a lifting device which operates in two planes and includes a bin grasping device.
A further object of the invention is to provide a lifting device including an articulated arm disposed to pivot in one plane and rotatably attached to a refuse vehicle for pivoting in another plane and including a grasping device pivotally attached to the articulated arm for pivoting in the same plane as the articulated arm.
Other objects, features, and advantages of the present invention will become apparent to those skilled in the art through familiarity with the summary of the invention, detailed description, claims, and drawings herein.
The foregoing and other objects of the present invention, are attained by providing a lifting device including a swivel mount or turret which rotates in a generally horizontal plane, i.e., parallel to the deck of a vehicle on which it is mounted such as a refuse vehicle and an articulated arm connected to the swivel mount. The swivel mount includes a housing which rotates about a shaft connected to one or more support plates which are, in turn, attached to the vehicle. The articulated arm is attached to the housing and includes first and second arm members joined or articulated to one another, at one end. The first arm member is pivotally attached at a second end to an arm pivot support attached to the housing and the second arm member has a free end which carries a gripping or grasping mechanism. The articulated arm pivots in a generally vertical plane to provide a lift and dump function.
In one embodiment, the swivel mount includes a base plate attached to the frame of a vehicle and upper and lower parallel pivot plates attached to the base plate and carrying a shaft therebetween. The housing member is engaged on the shaft and a lever arm is attached to the housing member. The lever arm or crank is connected to the rod end of a hydraulic cylinder attached to the frame or a frame extension of the vehicle and which reciprocates to rotate the housing member. The housing member rotates in a plane parallel to the deck or frame of the vehicle. The arm base pivot is attached to the housing member such that the articulated arm is disposed to pivot in a generally vertical plane essentially perpendicular to the plane of rotation of the swivel mount. The grasping device is pivotally connected to the second or outer arm member of the articulated arm so as to pivot in the same plane as the articulated arm. One embodiment of the grasping device further uses a plurality of opposed digits which may be articulated and which open and close to release and capture a standing container of any cross sectional shape.
In operation, at the beginning of a lift and dump cycle the digits of the grasping device are in an xe2x80x9cas stowedxe2x80x9d or open position and the articulated arm is extended to move the grasping device toward the container of interest. The swivel mount is pivoted to move the grasping device into engagement with the container of interest. The grasping device is operated to a closed position to grab the container and the articulated arm is operated generally vertically to lift and tip or invert the container and empty the contents into a receiving hopper of the vehicle. During the lifting and dumping operation, the swivel mount need not be operated since the arm and grasping device tilt the container above the swivel mount regardless of the selective rotational position of the swivel mount.
In another embodiment, the swivel mount includes a rotary actuator, such as a rack and pinion or beveled gears including a worm gear and planetary gear or other device such as a rotary hydraulic actuator, to pivot the housing member about a shaft which is carried by a single lower pivot plate attached to a base plate which, in turn, is fixed to the frame. The articulated arm and grasping device are attached to the housing member connected to pivot in a generally vertical plane which is perpendicular to the plane of rotation of the housing member.
One grasping device suitable for any embodiment of the invention has a pair of spaced, opposed arms or digits pivotally connected to a central support member. The arms are shaped to fit around containers of a plurality of different shapes, including curved, rectangular, hexagonal and others. The arms are pivoted between an open or retracted position in a closed or grasping position by fluid-operated actuators, such as hydraulic cylinders. The arms may be either single or plural member type arms having curvilinear shape and in one embodiment shown, the plural member or articulated dual arm embodiment is described in which each arm has an inner member pivotally connected at one end to a common support member and an outer member pivotally connected to a corresponding inner member. The fluid-operated actuators, such as double acting hydraulic cylinders, are pivotally connected between each outer member and the common support member. The pivot points of the arms are closer together and closer to the container of interest than those of the actuators on the common support to provide leverage and allow the arms to grasp the container of interest on the power stroke of the double acting hydraulic cylinders.
While the detailed embodiments are devoted to refuse trucks, the lifting device of the present invention may be mounted on other vehicles including dump trucks or even as a stationary loader. In situations where the lifting device is attached to a vehicle, the swivel mount may be attached to either the frame (chassis) of the vehicle or to a material receiving body of the vehicle, such as the storage body of the refuse truck or dump body of a dump truck. In this configuration, the lifting device is lifted with the storage body or dumping body to a raised position during the dumping operations.